Hello, hello, I am Dabai (●—●)
lambda expression
Lambda expressions can be seen as a concise way of writing anonymous inner classes.
Grammatically, Lambda expressions consist of three parts:
parameter list, arrow, and body, such as :
(parameters)->expression
or
(parameters)->{statements}
Functional interface
Lambda expressions used in the function interface, so-called functional interfaces, only defines an abstract method interface (Interface)
if there is a default interface method does not affect
comment @FunctionalInterface can help us to prevent errors in the design of functional interfaces
we Commonly used Runnable and Callable are functional interfaces.
JDK8 has added several functional interfaces:
- Predicate<T>:
Contains the test method, receives the generic T, and returns boolean, which can be regarded as an assertion (check) interface - Consumer<T>:
Contains the accept method, receives the generic T, no return, can be regarded as a data consumption interface - Function<T, R>:
Contains the apply method, receives the generic T, and returns R, which can be regarded as a mapping conversion interface
ps: The new function interfaces are more than these, but simple usage is introduced. improve together
Dabai (●—●) accompany you to make progress together!
